What are the factors influencing NFC RFlD tags'read distance?

For all RFID and NFC tags, the size is larger, its read distance would be longer. And when length=width, its read distance would be best among length>width and length<width. 

The factors influencing reading distance: are reader antenna size, read amplifier power, both of reader and tags’ frequency, NFC tag’s antenna size and using environment (like using underwater, on metal, and others) 

It is hoped to know the customer’s environment, if you don’t know select which chip type, and if you want reading distance to be better, please contact us, and we can help to adjust a good frequency for you.